2005-06-10

Patrick Durusau, in the title post on Topic Maps ISO/IEC SC34 list, questions the notion of "subject locators" as defined by TMDM. His point is that through the network you never retrieve a resource, only some representation of it, depending on many things, including the global state of the client-server system at retrieval time, the state of the resource itself etc. Patrick quotes excerpts from the Thomas Fielding dissertation supporting such a view:

The early Web architecture defined URI as document identifiers. Authors were instructed to define identifiers in terms of a document's location on the network. Web protocols could then be used to retrieve that document. However, this definition proved to be unsatisfactory for a number of reasons ...

I tend more and more to agree with Patrick that this distinction TM make between "subject identifiers" and "subject locators", IOW between "subject indicator references" and "resource references" is certainly something to revisit. More on the thread ...